Lucie Krenek

Complication rates following open reduction and internal fixation of ankle fractures.

BACKGROUND Ankle fractures are among the most common injuries treated by orthopaedic surgeons. The purpose of the present investigation was to examine the risks of complications after open reduction and internal fixation of ankle fractures in a large population-based study. METHODS With use of Californias discharge database, we identified 57,183 patients who had undergone open reduction and internal fixation of a lateral malleolar, bimalleolar, or trimalleolar ankle fracture as inpatients in the years 1995 through 2005. Short-term complications were examined on the basis of the rates of readmission within ninety days after discharge. The intermediate-term rate of reoperation for ankle fusion or arthroplasty was also analyzed. Logistic regression and proportional hazard regression models were used to determine the strength of the relationships between the rates of complications and fracture type, patient demographics and comorbidities, and hospital characteristics. RESULTS The overall rate of short-term complications was low, including the rates of pulmonary embolism (0.34%), mortality (1.07%), wound infection (1.44%), amputation (0.16%), and revision open reduction and internal fixation (0.82%). The intermediate-term rates of reoperation were also low, with ankle fusion or ankle replacement being performed in 0.96% of the patients who were observed for five years. Open fractures, age, and medical comorbidities were significant predictors of short-term complications. The presence of complicated diabetes was a particularly strong predictor (odds ratio, 2.30; p < 0.001), as was peripheral vascular disease (odds ratio, 1.65; p < 0.001). The intermediate-term rate of reoperation for ankle fusion or replacement was higher in patients with trimalleolar fractures (hazard ratio, 2.07; p < 0.001) and open fractures (hazard ratio, 5.29; p < 0.001). Treatment at a low-volume hospital was not significantly associated with either the aggregate risk of short-term complications or the risk of intermediate-term reoperation. CONCLUSIONS By analyzing a large, diverse patient population, the present study clarifies the risks associated with open reduction and internal fixation of ankle fractures. Open injury, diabetes, and peripheral vascular disease were strong risk factors predicting a complicated short-term postoperative course. Fracture type was a strong predictor of reoperation for ankle fusion or replacement. Hospital volume did not play a significant role in the rates of short-term or intermediate-term complications.

Influence of BMPs on the Formation of Osteoblastic Lesions in Metastatic Prostate Cancer

The purpose of this study was to evaluate the role of BMPs on the formation of metastatic prostate cancer lesions to bone. Our results show that BMPs influence the development and progression of osteoblastic lesions and suggest that therapies that inhibit BMP activity may reduce the formation and progression of osteoblastic lesions.

Mixed Metastatic Lung Cancer Lesions in Bone Are Inhibited by Noggin Overexpression and Rank:Fc Administration

Lung cancer metastases to bone produce a primarily mixed osteolytic/osteoblastic lesion. The purpose of this study was to determine if blockade of both pathways would inhibit the formation these lesions in bone. Inhibition of the osteoblastic lesion with noggin and the osteolytic lesion with RANK:Fc was a successful treatment strategy to inhibit progression of mixed lung cancer lesions in bone.

Stem cells from human fat as cellular delivery vehicles in an athymic rat posterolateral spine fusion model.

BACKGROUND Mesenchymal stem cells derived from human liposuction aspirates, termed processed lipoaspirate cells, have been utilized as cellular delivery vehicles for the induction of bone formation in tissue engineering and gene therapy strategies. In this study, we sought to evaluate the efficacy of bone morphogenetic protein (BMP)-2-producing adipose-derived stem cells in inducing a posterolateral spine fusion in an athymic rat model. METHODS Single-level (L4-L5) intertransverse spinal arthrodesis was attempted with use of a type-I collagen matrix in five groups of athymic rats, with eight animals in each group. Group I was treated with 5 x 10(6) adipose-derived stem cells transduced with an adenoviral vector containing the BMP-2 gene; group II, with 5 x 10(6) adipose-derived stem cells treated with osteogenic media and 1 microg/mL of recombinant BMP-2 (rhBMP-2); group III, with 10 microg of rhBMP-2; group IV, with 1 microg of rhBMP-2; and group V, with 5 x 10(6) adipose-derived stem cells alone. The animals that showed radiographic evidence of healing were killed four weeks after cell implantation and were examined with plain radiographs, manual palpation, microcomputed tomography scanning, and histological analysis. RESULTS All eight animals in group I demonstrated successful spinal fusion, with a large fusion mass, four weeks postoperatively. Furthermore, group-I specimens consistently revealed spinal fusion at the cephalad level (L3 and L4), where no fusion bed had been prepared surgically. In contrast, despite substantial BMP-2 production measured in vitro, group-II animals demonstrated minimal bone formation even eight weeks after implantation. Of the groups treated with the application of rhBMP-2 alone, the one that received a relatively high dose (group III) had a higher rate of fusion (seen in all eight specimens) than the one that received the low dose (group IV, in which fusion was seen in four of the eight specimens). None of the group-V animals (treated with adipose-derived stem cells alone) demonstrated successful spine fusion eight weeks after the surgery. CONCLUSIONS Adipose-derived stem cells show promise as gene transduction targets for inducing bone formation to enhance spinal fusion in biologically stringent environments.

Factors predicting complication rates after primary shoulder arthroplasty.

HYPOTHESIS Shoulder arthroplasty is an effective treatment for arthritic conditions and intraarticular fractures of the proximal humerus. Treatment options include total and hemiarthroplasty of the shoulder. They hypothesis of this study was that a mandatory statewide discharge database could identify the epidemiology of primary shoulder arthroplasty, 90 day complication rates, implant survival rates, and patient and hospital characteristics associated with complications. MATERIALS AND METHODS We identified patients undergoing primary total shoulder replacement and hemiarthroplasty between 1995 and 2005. We report rates of complications within 90 days of surgery and performed survival analysis using revision surgery as the endpoint. Logistic and proportional hazard regression models were used to estimate the effect of patient and provider factors in predicting the rates of adverse outcomes. RESULTS During the study period, 15,288 patients underwent shoulder arthroplasty. Patients undergoing total shoulder arthroplasty and hemiarthroplasty had no statistically significant difference in the aggregate risk of 90-day complications or the risk of implant failure within the study period. Fracture patients were shown to have a higher risk of short-term complications (odds ratio, 3.2; P < .001). Implant failure rates were lower in patients with fracture, rheumatoid arthritis, increased comorbidity, and advanced age. CONCLUSION This study reports similar rates of short-term complications and implant failure in patients undergoing total or hemiarthroplasty, an overall mortality rate of 1.3%, and a pulmonary embolism rate of 0.6%. The findings of our study indicate that the risk of short-term complications is highest in patients undergoing total or hemiarthroplasty for a fracture compared with nonfracture indications. Our results also indicate that longer-term, implant survival is largely driven by factors associated with increased activity, such as age. In patients undergoing surgery for arthritis of the shoulder, we found no difference in implant survival rates between total and hemiarthroplasty of the shoulder.

Complication and revision rates following total elbow arthroplasty.

PURPOSE To determine the complication rates after total elbow arthroplasty (TEA) in a large and diverse patient population. METHODS We identified patients undergoing TEA as inpatients in the years 1995 to 2005 using Californias Discharge Database. Short-term outcomes of interest included rates of infection or wound complications, revision, reoperation, and pulmonary embolism that were diagnosed during an inpatient hospital admission and mortality within 90 days of index surgery. Longer-term outcomes analyzed included rates of revision, amputation, and conversion to fusion. We used regression models to estimate the role of patient and provider characteristics in predicting the rates of adverse outcomes. RESULTS We identified 1,625 patients undergoing TEA. Early complications, defined as those requiring inpatient re-admission within the first 90 days after index surgery, were identified in 170 patients, and 132 patients required reoperation. Eighty one patients required revision in 90 days, and 48 underwent revision within one year. Early infections and wound complications requiring readmission occurred in 88 patients. In the 90 days after surgery, 4 patients had a pulmonary embolism and 10 patients died. One-hundred and twenty-one patients required revision, amputation, or fusion during the observation period, with a mean follow-up of 4 years. Hospital volume was not associated with increased risk of adverse outcomes. CONCLUSIONS We analyzed a large and diverse patient population undergoing TEA. The overall rate of short-term complications requiring inpatient treatment was high, at over 10% (170 patients), with almost 8% (132 patients) requiring reoperation within the first 90 days. Although population-based studies have shortcomings, they can add to the body of knowledge of less frequent procedures such as TEA. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic IV.

Incidence and factors predicting pulmonary embolism and deep venous thrombosis following surgical treatment of ankle fractures

BACKGROUND The purpose of this study was to identify the incidence and risk factors associated with pulmonary embolism and deep venous thrombosis following open reduction and internal fixation of ankle fractures. METHODS This was a retrospective study of patients in California undergoing operative treatment of an ankle fracture from 1995 to 2005. The main outcome measure was readmission for pulmonary embolism or deep venous thrombosis within 90 days of surgery. RESULTS A total of 57,183 patients from the California discharge database were identified. The readmission rate for pulmonary embolism was low at 0.34%. The risk was increased in patients aged 50-75, those with open fractures, and those with higher Charlson comorbidity score. The overall rate of readmission for deep venous thrombosis was also low at 0.05%. CONCLUSIONS The overall rate of thromboembolic disease was low in this large patient sample. Increased age and comorbidity were associated with an increased risk.

Complication rates following operative treatment of calcaneus fractures.

BACKGROUND The purpose of this study is to report the short-term complication rates and mid-term subtalar fusion rates following operative management of calcaneal fractures. METHODS This is a retrospective study of Californians undergoing operative treatment of a calaneus fracture from 1995 to 2005. The main outcomes reported are readmission for a short-term complication within 90 days of surgery and reoperation for subtalar fusion during the observation period. RESULTS We identified 4481 patients who underwent open reduction and internal fixation of their fracture as inpatients within 30 days of the index admission. The short-term rate of complications included a 90-day rate of readmission of 1.03% for wound infection, 0.25% for thromboembolic disease, and 0.22% for mortality. The mid-term rate of subtalar fusion was 3.49% at 5 years post-operatively. CONCLUSIONS This study reports the short-term complication rates and mid-term subtalar fusion rates following operative management of calcaneal fractures using population-based data.

Variations in the quality of care delivered to patients undergoing total knee replacement at 3 affiliated hospitals.

While excellent clinical results have been seen with total knee replacement (TKR), extensive documentation exists in variations in outcomes due to factors such as hospital and surgeon volume. The hypothesis of this study was that statistically significant variation exists in the processes of care delivered to patients undergoing TKR at 3 affiliated hospitals.Retrospective chart review was used to compare the quality of care delivered to a sample of patients from an academic medical center, public county hospital, and private community hospital. Two hundred twenty-four patients undergoing primary TKR were included. Quality of care was measured by determining adherence to a set of 31 evidence-based quality indicators created using the RAND/UCLA modified Delphi expert panel methodology. The overall rate of adherence to the quality indicators was 53% (95% confidence interval [CI], 52%-55%) for the 224 patients. There was a statistically significant difference between sites, with patients treated at the high-volume academic center demonstrating a 58% rate of adherence (95% CI, 56%-61%) compared with 50% (95% CI, 48-51%; P =.008) at the lower-volume public hospital and 52% (95% CI, 51%-54%; P =.03) at the lower-volume private hospital.Further study is warranted to determine the extent of variation in the delivery of care and its relationship to variation in outcomes of care for patients undergoing TKR.

Elevated Risks of Ankle Fracture Surgery in Patients With Diabetes

A nkle fractures are one of the most common types of injuries treated by orthopedic surgeons. For the majority of patients, results are satisfactory, and most are able to return to their pre-injury level of functioning. However, for a minority, a seemingly straightforward ankle fracture can be devastating, resulting in wound complications, multiple reoperations, and, for some, amputation. Previous studies have shown that certain patients are more likely to suffer from these complications, particularly those with impaired wound healing. Patients predisposed to impaired wound healing may include, among others, those with diabetes or peripheral vascular disease and those taking steroid medications. In todays aging population, diabetes is common and on the rise, making it vital that treatment teams be aware of potential pitfalls in their treatment. The purposes of this study were to determine the rates of wound infection, reoperation, and amputation after surgical treatment of ankle fractures in patients with diabetes and to quantify the increased risk of these complications in a large, diverse patient population. Clarifying the magnitude of risk and the rates of these complications will assist orthopedic surgeons and medical consultants in the treatment and the counseling of patients with these conditions. The strength of this study lies in the large, diverse patient sample, in which multiple races, ages, comorbidities, and provider characteristics are represented. We hypothesized that the risk of wound infection, revision surgery, and amputation after surgical treatment of ankle fractures would be higher in patients with diabetes compared to patients without these conditions. In addition, we hypothesized that patients with complicated diabetes would have a higher risk of these complications compared to both patients without diabetes and those with uncomplicated diabetes. ### Data source Data for all hospital discharges in California in the years 1995–2005 were obtained from Californias Office of Statewide Health Planning and Development …